Ice-Lined Refrigerator (ILR) vs Vaccine Refrigerator vs Deep Freezer in India's Cold Chain

An ice-lined refrigerator (ILR) is the top-opening, 2–8°C vaccine refrigerator used at cold chain points in India’s Universal Immunization Programme (UIP); its ice lining keeps vaccines safe through long power cuts. A deep freezer runs at -15°C to -25°C and, at PHC level, is used only to freeze ice packs. A vaccine or pharmacy refrigerator is a purpose-built 2–8°C cabinet used by hospitals, clinics and pharmacies, and depends on mains or backup power rather than an ice lining. The three are designed for different jobs and suit different sites.

WinHyCare does not supply ILRs. We supply pharmacy and vaccine refrigerators and portable coolers, and wrote this guide because buyers often search for one when they need another.

Side-by-side comparison

	Ice-lined refrigerator	Deep freezer	Pharmacy / vaccine refrigerator	Domestic refrigerator
Temperature	+2°C to +8°C	-15°C to -25°C	+2°C to +8°C	+2°C to +8°C
Holdover in a power cut	20 h minimum at 43°C (MoHFW spec)	2 h 30 min minimum at 43°C	Model-dependent; plan backup power	About 4 h (MoHFW)
Main use	UIP vaccine storage at PHC and district	Freezing ice packs; OPV at district	Hospital, clinic and pharmacy stock	Not recommended for vaccines

Sources: MoHFW Immunization Handbook, Table 4.1 and pp. 87–90; WHO PQS E003.

How an ILR works

MoHFW describes the design: “Inside the ILR there is a lining of water containers (ice packs or tubes) fitted all around the walls and held in place by frame”, and “if the electricity supply fails, then the ice lining maintains the inside temperature of the refrigerator at a safe level for vaccines” (Handbook for Vaccine & Cold Chain Handlers, pp. 18–19). The top-opening lid matters too: an ILR “with a top-opening lid prevents loss of cold air during door opening and can keep vaccines safe with as little as 8 hours electricity supply in a 24-hour period” (MoHFW, p. 87).

ILRs come in two sizes, large for districts and small for PHCs (p. 87). MoHFW defines holdover as “the time taken by the equipment to raise the inside cabinet temperature from its cut-off temperature to the maximum temperature limit of its recommended range”, and lists what shortens it: higher ambient temperature, frequent lid opening, how the basket is used, and the condition of the ice lining (p. 85).

WHO treats the ILR as a sub-type of the ordinary vapour-compression refrigerator and states that most ILRs “can maintain acceptable temperatures below +8°C on as little as eight hours of electricity per 24 hours”, with the ice store keeping vaccine cool “for at least 20 hours” when power fails (WHO PQS E003). WHO’s guidance is that ILRs “are the preferred option where there is reliable mains electricity for at least eight hours per day” (Immunization in Practice, Module 2).

The freezing risk at the bottom

The ice lining is also the ILR’s weakness. “During the refreezing process some areas of an ILR can fall below 0°C – e.g. the bottom of the compartment. For non-grade A appliances freeze-sensitive vaccines should NEVER be stored within 150 mm of the base” (WHO PQS E003). Since 2016, WHO grades appliances A, B or C for freezing risk; grade A appliances “are certified as low vaccine freezing risk even if baskets are not used”.

Loading rules

MoHFW’s rules for the ILR (Table 4.2, p. 88):

• Keep all vaccines, including opened vials under the open vial policy, in the basket supplied with the ILR. Never keep vaccines on the floor of the ILR.
• Keep freeze-sensitive vaccines at the top of the basket and heat-sensitive vaccines at the bottom.
• Do not store other drugs or non-UIP vaccines in the ILR, and do not keep food or drinking water in it.
• Connect each ILR or deep freezer to the mains “through its own independent voltage stabilizer with proper earthing” (p. 90).

What the deep freezer is for

“Freezing ice packs in the DF maintains the cabinet temperature between -15°C and -25°C. At the PHC level, DF is used only for preparation of ice packs. At the district headquarters, DFs have been supplied for storage of recommended vaccines such as OPV and preparation of ice packs” (MoHFW, p. 88). MoHFW adds two prohibitions: “Do not keep any vaccine in the DF at sub-district level” and “Never keep diluents in the deep freezer” (Table 4.3).

A deep freezer “does not have holdover time like ILR as it does not have an ice lining inside its wall”, which is why its specified minimum holdover is only 2 hours 30 minutes at 43°C (p. 85). WHO’s storage guidance matches the programme’s split: “With a few exceptions, vaccines should be stored at +2°C to +8°C”, while “OPV should be stored in freezers at -25°C to -15°C in primary and subnational stores” (WHO VMH-E2, §2.2).

A cold chain point combines both: it is “located at a health centre (usually PHC/UHC/CHC) with an Ice Lined Refrigerator for storage of vaccines and a deep freezer for preparation of frozen ice packs” (MoHFW, p. 86).

Where a vaccine or pharmacy refrigerator fits

The UIP rule that non-UIP vaccines and other drugs must not go into the ILR means private hospitals, clinics and pharmacies need their own 2–8°C storage. MoHFW notes that urban dispensaries and private practitioners use domestic refrigerators, but these have “a holdover time of only 4 hours. Therefore, they are not recommended for common use in the UIP” (p. 90). WHO is blunter: “Domestic refrigerators and freezers should never be used to store vaccines” (WHO PQS E003), and “WHO recommends that only prequalified refrigerators be purchased” for programme vaccine storage (VMH-E2, §5.2.3).

The US CDC ranks suitable units for clinics: purpose-built and pharmaceutical-grade units ahead of household units, and “Never use dormitory- or bar-style combined refrigerator/freezer units for vaccine storage” (CDC toolkit, Section Three).

A purpose-built pharmacy refrigerator differs from an ILR in what it optimises. It gives tight temperature control, alarms and records, and front access to large stock; it does not have an ice lining, so long power cuts must be covered by a generator or UPS. WinHyCare’s models are listed below. They are not WHO PQS-prequalified and are not a substitute for the ILRs procured for government cold chain points.

Model	Capacity	Temperature	Features
WPC-5V730S	730L	2–8°C, ±0.1°C accuracy	Forced air, self-closing glass door, alarms, USB export
WPC-5V1000S	1000L	2–8°C, ±0.1°C accuracy	Forced air, self-closing glass door, alarms, USB export
WPC-5V1500	1500L	2–8°C, ±0.1°C accuracy	Three glass doors, 12 shelves, alarms, USB export
WRF-25V528	273L + 255L	2–8°C and -10°C to -25°C	Refrigerator and freezer in one cabinet

Freeze damage and the shake test

Freezing destroys several common vaccines. MoHFW lists HepB, Penta and PCV as freezing at -0.5°C, and IPV, DPT and TT at -3°C, all of which “should not be frozen”; OPV is “not damaged by freezing” (Table 4.5, p. 95). Conditioning ice packs before use “prevents freezing of vaccines (freeze-sensitive vaccines such as Hep B and T series) during transportation” (p. 93).

Where freezing is suspected, the shake test compares a suspect vial against a control vial frozen solid “at -20°C overnight in the DF”. If the suspect vial’s sediment settles at the same rate or faster than the frozen control, “the vaccine is damaged … Do NOT use”. The shake test is not applicable for IPV (pp. 96–97).

Transport: carriers and cold boxes

• Vaccine carrier: “Vaccine carrier (with 4 conditioned ice packs) maintains the inside temperature between +2°C and +8°C for 12 hours, if not opened frequently” (p. 99).
• Cold box: used to “store vaccines for transfer up to 5 days, if necessary for outreach sessions or when there is a power cut”, and to hold vaccines if an ILR breaks down (p. 91).
• Long power cuts: for outages of more than 16 hours a day, MoHFW advises an alternate power source for at least 8 hours a day, or transferring vaccines to a cold box, “which can hold the vaccines for 72 hours if not opened” (Table 4.12, p. 109).

Carriers and cold boxes are passive. For vehicle-based transfers with power available, a compressor-powered portable cooler with a 2–8°C mode is another option for hospitals and private providers.

Temperature monitoring

MoHFW defines a cold chain break as a temperature “above +8°C or falls below +2°C in the ILR and above -15°C in the DF” (p. 100). Temperatures are recorded twice daily, and the logbook is kept for at least three years (Table 4.9, p. 103). WHO’s guidance is similar: manual recording “twice a day, seven days a week in large vaccine stores and at least five days a week in smaller subnational vaccine stores and health facilities” (VMH-E2).

India’s programme also monitors equipment electronically. The Electronic Vaccine Intelligence Network (eVIN), “conceptualized and piloted by the Immunisation Technical Support Unit (ITSU), MoHFW”, uses automated loggers that “monitor and record the storage temperatures of ILRs, DFs, WICs and WIFs” (MoHFW, pp. 121–123). The national cold chain management information system was developed in 2010 by MoHFW with support from UNICEF India (p. 120), and the handbook describes a network of about 27,000 cold chain points (Part 1, p. 6).

Which one do you need?

Your site	Equipment
Government PHC, CHC or district store in the UIP	ILR and deep freezer, procured through the programme
Private hospital, clinic or pharmacy storing vaccines	Purpose-built 2–8°C vaccine or pharmacy refrigerator with backup power
Site that also needs frozen storage	Combined refrigerator-freezer, or a separate -40°C medical freezer
Outreach and transfers	Vaccine carriers and cold boxes; powered coolers for vehicles